Abstract: Insufficient memory is the bottleneck problem for large scale transport simulation using Monte Carlo methods. When doing reactor burnup analysis, excessive reaction cross sections are required to be tallied in transport step, thereby the scale of depletion is restricted by the memory storage of computers. To address this problem, a combined parallel method is proposed and implemented in Reactor Monte Carlo code RMC. Tally data is distributed in parallel processes by using tally data decomposition algorithm, which is coupled with the parallel point depletion module. Full core benchmark tests are carried out. The results illustrate that the memory footprint are reduced evidently by using the combined parallel method. It is demonstrated that the data decomposition methods are effective to realize the full core burnup calculations.